TRENTON — Gov. Chris Christie said he’d support the extension of New York City’s No. 7 subway to Secaucus, offering more commuters direct Manhattan access.

New Jersey will “do our share” if New York state and the city contribute to the financing, Christie said in a WCBS radio interview yesterday. “All of this will be able to come together.”

Christie last year killed an $8.7 billion commuter rail tunnel, intended to double rush-hour capacity, because of concern that New Jersey would be responsible for as much as $5 billion in additional costs. New York Mayor Michael Bloomberg then proposed to extend the crosstown subway to northern New Jersey.

“This is something where the economics seem to make some sense,” Bloomberg told reporters Wednesday. “We could work with New Jersey and the federal government and the state government here to get some money to do it.”

The No. 7 subway, which travels between the borough of Queens and Times Square, is already being extended to the West Side of Manhattan by the Metropolitan Transportation Authority to serve Related Co.’s Hudson Yards riverside development.

In March, Christie said he’d be willing to consider another rail tunnel so long as New York state and city helped pay for it.

The mayor is founder and majority owner of Bloomberg News’s parent, Bloomberg LP.